1. Field of the Invention
The present invention relates to a method for screening an anticancer candidate.
2. Description of the Related Art
Localized surface plasmon resonance (LSPR) has been used extensively in a number of studies on interactions between surface-immobilized biomolecules due to its ability to quantitatively detect reactions without the need for complicated preliminary purification and labeling steps. According to LSPR, when light of various wavelengths is irradiated onto metal nanoparticles as surface-localized materials, polarization occurs on the surface of the metal nanoparticles and is responsible for their unique properties, such as enhanced electric field intensity. This physical phenomenon does not occur in a bulk metal. The optical properties of LSPR respond sensitively to changes in the dielectric constant (refractive index) near the surface of nanoparticles, allowing such dielectric constant (refractive index) changes to be used to detect adsorption between biomolecules.
STAT3 protein is a transcriptional regulatory factor involved in the transcription of several genes in human cells. In normal cases, STAT3 present in the cytoplasm translocates into the nucleus and regulates genes for cell development, differentiation, growth, survival, angiogenesis, and immune functions in response to signaling by extracellular cytokines and growth factors. It is also known that STAT3 protein is persistently activated through various pathways and promotes tumorigenesis. Studies on the functions of STAT3 protein in carcinogenesis and metastasis demonstrate that when excessively activated, STAT3 protein is closely related to cancer angiogenesis and metastasis. In addition to these, STAT3 is known to play a central role in the initiation, development, and progression of tumors, including cancer growth, anti-apoptosis, anticancer resistance in the invasive tumor microenvironment, and immune escape. Persistent activity of STAT3 is closely related to a broad range of human tumors. Thus, STAT3 is considered a new target for tumor prevention and therapy.